1. Field of the Invention
The present invention relates to a brake apparatus for a vehicle, and to a method of using the described apparatus. More particularly, the present invention relates to a brake apparatus and method in which accuracy of zero-point corrections of multiple pressure sensors, provided in a brake pipe path, is improved.
2. Description of the Background Art
There is a known a hydraulic brake apparatus having the following configuration employed in vehicles such as motorcycles. Specifically, in the known hydraulic brake device, an input side in which hydraulic pressure is generated by a rider performing a brake operation, and an output side in which the hydraulic pressure is applied to a brake caliper so as to brake (to stop rotation of) a wheel, are connected to and disconnected from each other by a solenoid valve.
The Japanese Patent Application Publication No. 2006-193136 discloses a brake apparatus in which a master cylinder which generates hydraulic pressure in conjunction with the operation of a brake lever is connected to a brake caliper which generates a brake force with the hydraulic pressure supplied thereto, by a brake path including a normally-open solenoid valve, and in which a hydraulic modulator which generates hydraulic pressure in an actuator is connected to a brake caliper side by the solenoid valve. The brake apparatus of this type is configured, when a brake operation force is detected by the pressure sensor, to close the normally-open solenoid valve and perform drive control of the hydraulic modulator based on an output value from the pressure sensor so that the brake caliper generates a brake force.
In order to appropriately control such brake devices, multiple sensors are necessary to detect the pressure in a hydraulic pressure passage. In the configuration as disclosed in the Japanese Patent Application Publication No. 2006-193136, two input side pressure sensors and one output side pressure sensor are provided.
In the configuration in which the drive control of the brake apparatus is performed based on the output values of the multiple pressure sensors as described in the Japanese Patent Application Publication No. 2006-193136, it is preferable to have high resolution pressure sensors on the input side which detects the brake operation force by the rider, in particular. When the high resolution pressure sensors are provided, the accuracy of the brake control can further be improved by performing a correction of adjusting the zero points of the other pressure sensors to that of the high resolution pressure sensor.
However, the pressure sensor tends to decrease in pressure resistance when the resolution is improved, which in turn causes a problem that the high resolution pressure sensor should not be arranged in a place where there is a possibility of an excessive hydraulic pressure being generated. In the configuration described in the Japanese Patent Application Publication No. 2006-193136, a structural arrangement to cope with the problem, appropriate steps of the zero-point correction, and the like have not been taken into consideration.
The present invention has been made to overcome such drawbacks of existing hydraulic brake apparatus. Accordingly, it is one of the objects of the present invention to solve the problem of the related art described above, and to provide a brake apparatus for a vehicle in which the accuracy of the zero-point corrections of multiple pressure sensors provided to a brake pipe path can be improved.